[PATCH] drm/amd/display: Fix mst hub unplug warning

[Wayne Lin]

[Why]
Unplug mst hub will cause warning. That's because
dm_helpers_construct_old_payload() is changed to be called after
payload removement from dc link.

In dm_helpers_construct_old_payload(), We refer to the vcpi in
payload allocation table of dc link to construct the old payload
and payload is no longer in the table when we call the function
now.

[How]
Refer to the mst_state to construct the number of time slot for old
payload now. Note that dm_helpers_construct_old_payload() is just
a quick workaround before and we are going to abandon it soon.

Fixes: 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload 
allocation/removement")
Reviewed-by: Jerry Zuo <jerry....@amd.com>
Signed-off-by: Wayne Lin <wayne....@amd.com>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 38 +++++++++----------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index baf7e5254fb3..2f94bcf128c0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -204,15 +204,16 @@ void dm_helpers_dp_update_branch_info(
 {}
 
 static void dm_helpers_construct_old_payload(
-                       struct dc_link *link,
-                       int pbn_per_slot,
+                       struct drm_dp_mst_topology_mgr *mgr,
+                       struct drm_dp_mst_topology_state *mst_state,
                        struct drm_dp_mst_atomic_payload *new_payload,
                        struct drm_dp_mst_atomic_payload *old_payload)
 {
-       struct link_mst_stream_allocation_table current_link_table =
-                                                                       
link->mst_stream_alloc_table;
-       struct link_mst_stream_allocation *dc_alloc;
-       int i;
+       struct drm_dp_mst_atomic_payload *pos;
+       int pbn_per_slot = mst_state->pbn_div;
+       u8 next_payload_vc_start = mgr->next_start_slot;
+       u8 payload_vc_start = new_payload->vc_start_slot;
+       u8 allocated_time_slots;
 
        *old_payload = *new_payload;
 
@@ -221,20 +222,17 @@ static void dm_helpers_construct_old_payload(
         * struct drm_dp_mst_atomic_payload are don't care fields
         * while calling drm_dp_remove_payload_part2()
         */
-       for (i = 0; i < current_link_table.stream_count; i++) {
-               dc_alloc =
-                       &current_link_table.stream_allocations[i];
-
-               if (dc_alloc->vcp_id == new_payload->vcpi) {
-                       old_payload->time_slots = dc_alloc->slot_count;
-                       old_payload->pbn = dc_alloc->slot_count * pbn_per_slot;
-                       break;
-               }
+       list_for_each_entry(pos, &mst_state->payloads, next) {
+               if (pos != new_payload &&
+                   pos->vc_start_slot > payload_vc_start &&
+                   pos->vc_start_slot < next_payload_vc_start)
+                       next_payload_vc_start = pos->vc_start_slot;
        }
 
-       /* make sure there is an old payload*/
-       ASSERT(i != current_link_table.stream_count);
+       allocated_time_slots = next_payload_vc_start - payload_vc_start;
 
+       old_payload->time_slots = allocated_time_slots;
+       old_payload->pbn = allocated_time_slots * pbn_per_slot;
 }
 
 /*
@@ -272,8 +270,8 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
                drm_dp_add_payload_part1(mst_mgr, mst_state, new_payload);
        } else {
                /* construct old payload by VCPI*/
-               dm_helpers_construct_old_payload(stream->link, 
mst_state->pbn_div,
-                                               new_payload, &old_payload);
+               dm_helpers_construct_old_payload(mst_mgr, mst_state,
+                                                new_payload, &old_payload);
                target_payload = &old_payload;
 
                drm_dp_remove_payload_part1(mst_mgr, mst_state, new_payload);
@@ -366,7 +364,7 @@ bool dm_helpers_dp_mst_send_payload_allocation(
        if (enable) {
                ret = drm_dp_add_payload_part2(mst_mgr, mst_state->base.state, 
new_payload);
        } else {
-               dm_helpers_construct_old_payload(stream->link, 
mst_state->pbn_div,
+               dm_helpers_construct_old_payload(mst_mgr, mst_state,
                                                 new_payload, &old_payload);
                drm_dp_remove_payload_part2(mst_mgr, mst_state, &old_payload, 
new_payload);
        }
-- 
2.37.3